1. Field of the Invention
The present invention relates to wheeled luggage and more particularly to an improved locking pin of locking device for wheeled luggage.
2. Description of Related Art
A conventional wheeled luggage is equipped with two sets of wheel(s) and a retractable handle assembly which is either locked in a predetermined extended position while towing along ground or retracted to bezel on the top of luggage in an unused position. Such wheeled luggage is popular among travelers. In a typical extending operation, user may press a push button by grasping handle grip for causing locking pin to clear from an aperture of support tube through an activated flexible (or rigid) connection member such as steel cable which is coupled between the push button and the locking pin. Then it is possible of pulling sliding tube until a desired length of handle is reached. Finally, user may release push button to secure locking pin in another aperture for finishing the handle extension operation. Also, retracting operation is similar to above extending operation.
A portion of handle assembly of a wheeled luggage incorporating a conventional locking device is shown in FIGS. 5 and 6. The handle assembly comprises a handle grip 1 having a push button 2 on the intermediate portion, a sliding tube 3 extended downward from one end of handle grip 1, a support tube 4 for permitting sliding tube 3 to slide therein and having a bottom end fixedly coupled to bottom of luggage and a plurality of apertures (e.g., apertures 4B and 4C) on surface, a locking device 5 on lower portion of sliding tube 3, a flexible (or rigid) connection member such as steel cable 7 coupled between push button 2 and locking device 5, a locking pin 9 on lower end of locking device 5, and a spring 8 biased against inner end of locking pin 9 which is either projected into and locked in one of apertures (e.g., aperture 4B) in a normal position or disengaged from the aperture temporarily for being ready to extend or retract the handle. It is understood that almost all weight of luggage is borne on the engaged point of locking pin 9 and aperture (e.g., aperture 4B in FIG. 5) while towing. Hence, force exerted on locking pin 9 is huge. This is particularly true for a large luggage packed with personal items. In response, most locking pins 9 are formed of metal material for increasing structural strength thereof. However, the previous design suffered from several disadvantages. For example, loud sound or noise may be produced in retracting or extending operation due to a large friction between locking pin 9 and inner surface 4A of support tube 4. Further, inner surface 4A tends to wear. Hence, the structural strength of handle assembly may degrade after a long period of time of use.
Thus, it is desirable to provide an improved locking pin of locking device for wheeled luggage in order to overcome the above drawbacks of prior art.